You’ve probably heard this before…The consensus of scientists support…or 97% of scientists agree….
In 2017 NASA produced this report: Scientific Consensus: Earth’s Climate is Warming
The NASA report begins:
Multiple studies published in peer-reviewed scientific journals1 show that 97 percent or more of actively publishing climate scientists agree*: Climate-warming trends over the past century are extremely likely due to human activities. In addition, most of the leading scientific organizations worldwide have issued public statements endorsing this position. The following is a partial list of these organizations, along with links to their published statements and a selection of related resources.
The term “Scientific Consensus” has earned its own article at Wikipedia:
Scientific consensus is the collective judgment, position, and opinion of the community of scientists in a particular field of study. Consensus implies general agreement, though not necessarily unanimity.
Consensus is normally achieved through communication at conferences, the publication process, replication (reproducible results by others), and peer review. These lead to a situation in which those within the discipline can often recognize such a consensus where it exists, but communicating to outsiders that consensus has been reached can be difficult, because the ‘normal’ debates through which science progresses may seem to outsiders as contestation. On occasion, scientific institutes issue position statements intended to communicate a summary of the science from the “inside” to the “outside” of the scientific community. In cases where there is little controversy regarding the subject under study, establishing what the consensus is can be quite straightforward.
Scientific consensus may be invoked in popular or political debate on subjects that are controversial within the public sphere but which may not be controversial within the scientific community, such as evolution, climate change, or the lack of a link between MMR vaccinations and autism.
So, there you have it. If enough scientists agree on a scientific matter, it’s case closed. The science is “settled.”
Well, not so fast. Is “consensus” really the way science is done? Can it ever be said that, “The science is settled?”
I’ve found something that makes a point I find hard to overlook. It’s contained in a brilliant lecture at Caltech in 2003 by the late Dr. Michael Crichton (1942-2008). Crichton finished Harvard Medical School but never practiced medicine, opting instead to focus on writing and filmmaking. His works include The Andromeda Strain (1969), Jurassic Park(1990), State of Fear (2004), The Great Train Robbery (1979), Twister (1996), and ER (1994-2009).
The thing I’ve found, on Dr. Roy Spencer’s website, is a copy of a speech Michael Crichton gave at Caltech in 2003. It’s a great find because much of his brilliant work has been removed from the internet due to his refusal to drink the global warming/climate change kool-aid.
In that speech you will find what I consider to be the truth about “scientific consensus.” Crichton takes us back to the 1970s when “Nuclear Winter” was the fashionable crisis of the day:
In 1975, the National Academy of Sciences reported on “Long-Term Worldwide Effects of Multiple Nuclear Weapons Detonations” but the report estimated the effect of dust from nuclear blasts to be relatively minor. In 1979, the Office of Technology Assessment issued a report on “The Effects of Nuclear War” and stated that nuclear war could perhaps produce irreversible adverse consequences on the environment. However, because the scientific processes involved were poorly understood, the report stated it was not possible to estimate the probable magnitude of such damage.
Three years later, in 1982, the Swedish Academy of Sciences commissioned a report entitled “The Atmosphere after a Nuclear War: Twilight at Noon,” which attempted to quantify the effect of smoke from burning forests and cities. The authors speculated that there would be so much smoke that a large cloud over the northern hemisphere would reduce incoming sunlight below the level required for photosynthesis, and that this would last for weeks or even longer.
The following year, five scientists including Richard Turco and Carl Sagan published a paper in Science called “Nuclear Winter: Global Consequences of Multiple Nuclear Explosions.” This was the so-called TTAPS report, which attempted to quantify more rigorously the atmospheric effects, with the added credibility to be gained from an actual computer model of climate.
At the heart of the TTAPS undertaking was another equation, never specifically expressed, but one that could be paraphrased as follows:
Ds = Wn*Ws*Wh*T*Tb*Pt*Pr*Pe, etc.
(The amount of tropospheric dust = # warheads x size warheads x warhead detonation height x flammability of targets x Target burn duration x Particles entering the Troposphere x Particle reflectivity x Particle endurance, and so on.)
The similarity to the Drake equation [a silly attempt to estimate the likelihood of intelligent life in the universe, cf. Teejaw] is striking. As with the Drake equation, none of the variables can be determined. None at all. The TTAPS study addressed this problem in part by mapping out different wartime scenarios and assigning numbers to some of the variables, but even so, the remaining variables were — and are — simply unknowable. Nobody knows how much smoke will be generated when cities burn, creating particles of what kind, and for how long. No one knows the effect of local weather conditions on the amount of particles that will be injected into the troposphere. No one knows how long the particles will remain in the troposphere. And so on.
And remember, this is only four years after the OTA study concluded that the underlying scientific processes were so poorly known that no estimates could be reliably made. Nevertheless, the TTAPS study not only made those estimates, but concluded they were catastrophic.
According to Sagan and his coworkers, even a limited 5,000 megaton nuclear exchange would cause a global temperature drop of more than 35 degrees Centigrade, and this change would last for three months. The greatest volcanic eruptions that we know of changed world temperatures somewhere between 0.5 and 2 degrees Centigrade. Ice ages changed global temperatures by 10 degrees. Here we have an estimated change three times greater than any ice age. One might expect it to be the subject of some dispute.
But Sagan and his coworkers were prepared, for nuclear winter was from the outset the subject of a well-orchestrated media campaign. The first announcement of nuclear winter appeared in an article by Sagan in the Sunday supplement, Parade. The very next day, a highly-publicized, high-profile conference on the long-term consequences of nuclear war was held in Washington, chaired by Carl Sagan and Paul Ehrlich, the most famous and media-savvy scientists of their generation. Sagan appeared on the Johnny Carson show 40 times. Ehrlich was on 25 times. Following the conference, there were press conferences, meetings with congressmen, and so on. The formal papers in Science came months later.
This is not the way science is done, it is the way products are sold.
The real nature of the conference is indicated by these artists’ renderings of the effect of nuclear winter.
I cannot help but quote the caption for figure 5: “Shown here is a tranquil scene in the north woods. A beaver has just completed its dam, two black bears forage for food, a swallow-tailed butterfly flutters in the foreground, a loon swims quietly by, and a kingfisher searches for a tasty fish.” Hard science if ever there was.
At the conference in Washington, during the question period, Ehrlich was reminded that after Hiroshima and Nagasaki, scientists were quoted as saying nothing would grow there for 75 years, but in fact melons were growing the next year. So, he was asked, how accurate were these findings now?
Ehrlich answered by saying “I think they are extremely robust. Scientists may have made statements like that, although I cannot imagine what their basis would have been, even with the state of science at that time, but scientists are always making absurd statements, individually, in various places. What we are doing here, however, is presenting a consensus of a very large group of scientists.”
I want to pause here and talk about this notion of consensus, and the rise of what has been called consensus science. I regard consensus science as an extremely pernicious development that ought to be stopped cold in its tracks. Historically, the claim of consensus has been the first refuge of scoundrels; it is a way to avoid debate by claiming that the matter is already settled.
Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you’re being had.
Let’s be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus.
There is no such thing as consensus science. If it’s consensus, it isn’t science. If it’s science, it isn’t consensus. Period.
Crichton went on to demonstrate with actual cases that the track record of “consensus” is nothing to be proud of.